An introduction to perspective, drawing, and painting in a series of pleasing and familiar dialogues between the author's children : illustrated by appropriate plates and diagrams, and a sufficiency of practical geometry, and a compendium of genuine instruction ... (1820)
Hayter, Charles, 1761-1835 · London : Black, Kingsbury, Parbury, and Allen · leaf 328
263 A Scale for Proportion. may measure exactly one-half, one-third, fourth, fifth, sixth, seventh, or eighth, &c., part of the original, both in height and width; that the proportions may be the more easily compared. … from the side, parallel to the end, till either touches the diagonal, and from that point the corresponding width or length will be truly determined. THE END. Printed by J. F. Dove, St. John’s Square.
Perspective · Drawing · Painting · Color
Internet Archive · Getty Research Institute · Public domain (published before 1931). Free to use for anything.